The Christchurch City Council would be ''crazy'' to refuse an offer to repair earthquake-damaged Lancaster Park, an opponent of the proposed covered stadium says.

The Star reported that engineering work commissioned by insurer Civic Assurance showed the former AMI Stadium could be repaired for $45 million, which would sink ambitious plans for a $500m covered sports stadium in the city.

A council spokeswoman said today that the council had not been told about the findings.